Characterization of Carbamazepine-Loaded Solid Lipid Nanoparticles Prepared by Rapid Expansion of Supercritical Solution

Purpose: To prepare carbamazepine-loaded solid lipid nanoparticles (CBZ-SLN) for prolonged release of CBZ in oral drug delivery.
Methods: CBZ-loaded SLNs were prepared by rapid expansion of supercritical solution (RESS). SLNs were formulated using stearic acid as the lipid component. Initially, lipid and drug were separately micronized by RESS process separately. This was followed by co-precipitation of the components with the two solutes using RESS to produce drug-loaded SLNs. The formulations were characterized by infrared spectroscopy (IR), scanning electron microscopy (SEM) and ultraviolet spectrophotometry (UV).
Results: Application of RESS to pure stearic acid yielded spherical particles in the range 40 to 200 nm which was about 600 times smaller than the unprocessed powder based on SEM observation. Similarly, RESS processing of carbamazepine produced nanoparticles with rod shape. FT-IR analysis showed that no chemical structure change occurred during RESS processing of both components. Coprecipitation of drug and lipid using RESS produced SLNs with drug loading capacity of 2.2 %. RESS yielded ultrafine spherical particles (100 nm) of CBZ-SLNs.
Conclusion: The successful preparation and characterization of carbamazepine-loaded solid lipid nanoparticles by RESS as well as their characterization has been achieved in this study.

Keywords
Rapid expansion of supercritical fluid; Stearic acid; Solid lipid nanoparticles; Carbamazepine; Co-precipitation